1. Field of the Invention
The present invention relates to a control apparatus for controlling a regenerative operation of a vehicle motor.
Priority is claimed on Japanese Patent Application No. 2002-336688, filed Nov. 20, 2002, the content of which is incorporated herein by reference.
2. Description of Related Art
Conventionally, a charging apparatus for a battery assembly (battery) which is formed by connecting plural cell units of secondary batteries or the like to each other in series is known, in which the charging apparatus includes cell voltage measuring circuits and bypass circuits each being connected to each of the cell units, the charging apparatus determines whether each of the unit cells is in a fully charged state depending on an inter-terminal voltage measured by each of the cell voltage measuring circuits, makes charging current for any of the cell units which are determined to be fully charged to flow to the bypass circuits so that the inter-terminal voltages of the cell units are equalized with each other, and in addition, sets charging current for each of the cell units depending on the measured inter-terminal voltage (see, for example, Japanese Unexamined Patent Application, First Publication No. H04-299032).
Moreover, a type of vehicle is known in which the above-mentioned type of battery is installed as a driving power source, a driving motor is operated by supplying electrical power thereto from the battery, regenerated energy generated through a regenerative operation of the driving motor during a deceleration operation or the like of the vehicle is stored in the battery, and electrical energy is transmitted between the battery and the driving motor.
In the charging apparatus for a battery as an example of conventional technical measures, when it is determined that one of the cells is in a fully charged state, charging current to the specific cell is reduced to zero or to a level of self-discharging current. Accordingly, in the case in which the above-mentioned type of charging apparatus is installed in a vehicle, when it is determined that one of the cells is in a fully charged state when regenerated energy generated through a regenerative operation of the driving motor during a deceleration operation or the like of the vehicle is charged into the battery, the amount of regeneration by the driving motor is reduced to a level of zero or substantially zero. As a result, a rapid change in the deceleration operation of the vehicle, which is not expected by the driver, may occur, and thereby the driver may feel unusual sensations in the vehicle behavior.